U.S. Pat. No. 3,931,814 discloses a carburetor for an internal combustion engine, which has an electromagnetically operated valve. The valve is opened in synchronism with the cylinder intake phases. In order to adapt the quantity of fuel supplied, the opening times are varied as a function of operating parameters of the internal combustion engine.
In mixture-lubricated internal combustion engines, in particular in two-stroke engines or mixture-lubricated four-stroke engines, it is known to connect the intake channel to the crankcase of the internal combustion engine via a valve controlled by the piston skirt of a piston of the internal combustion engine. If the fuel is synchronously supplied to the intake tract via the fuel valve, the result is very short switching times of the valve, especially at high rotational speeds. As a result, a valve which reacts very quickly is needed. Because of the very frequent switching operations, especially at high rotational speeds, the service life of the valve is shortened.